Question

State the goal of an election al gorithm. Explain it detail.

Answer 1

Election algorithm basically determines where a new copy of coordinator should be restarted. Election algorithm assumes that every active process in the system has a unique priority number.

Answer 2

Election algorithm and distributed processing

Distributed Algorithm is a algorithm that runs on a distributed system. Distributed system is a collection of independent computers that do not share their memory. Each processor has its own memory and they communicate via communication networks. Communication in networks is implemented in a process on one machine communicating with a process on other machine. Many algorithms used in distributed system require a coordinator that performs functions needed by other processes in the system. Election algorithms are designed to choose a coordinator.

Election Algorithms:

Election algorithms choose a process from group of processors to act as a coordinator. If the coordinator process crashes due to some reasons, then a new coordinator is elected on other processor. Election algorithm basically determines where a new copy of coordinator should be restarted.

Election algorithm assumes that every active process in the system has a unique priority number. The process with highest priority will be chosen as a new coordinator. Hence, when a coordinator fails, this algorithm elects that active process which has highest priority number.Then this number is send to every active process in the distributed system.

We have two election algorithms for two different configurations of distributed system.

1. The Bully Algorithm –

This algorithm applies to system where every process can send a message to every other process in the system.